Emergency alert systems have been designed with a view to warn the public of an imminent threat or peril. For example, the AMBER plan (America's missing broadcast emergency response) is used in some countries by the law enforcement agencies to instantly galvanize the entire community to assist in the search and safe return of missing children. Also known are weather alert systems that transmit a special alarm tone over the radio networks with a view to advising about life-threatening situations. These systems are mostly used locally, in areas prone to natural hazards, such as zones of possible incidence of earthquakes, tsunamis, etc.
More complex emergency alert systems are also designed for advising the population of a larger geographical area (e.g. a country) about natural disasters, such as weather related phenomena, earthquakes, volcano activity, or technological hazards, such as chemical releases or oil spills. The idea at the basis of these systems is to minimize the loss of life and injuries. For example, the NOAA weather radio network is a US government service that broadcasts NWS (National Weather Service) warnings, watches, forecasts and other hazard information 24 hours a day from a network of over 600 radio transmitters located throughout a large area, including the mainland US and Puerto Rico, US Virgin Island, and US Pacific territories, etc.
The United States government currently makes use of an emergency alert system, named EAS (Emergency Alert System), which is designed to provide the president a means of addressing the public in the event of a national emergency, within 10 minutes of the need arising. Also, the system is used by local and state officials to broadcast emergency alert information.
However, the EAS is out of date and the FCC (Federal Communications Commission) has put forward proposal FCC 05-191, which is requesting the government, FCC and industry vendors to improve and update it. The goal is to include more popular user devices, since the existing EAS has support only for analog TV, analog radio, wireless cable, and wire line cable systems. There is a concern that a large number of people are moving away from these systems, which decreases the effectiveness of the EAS.
In October 2005, the FCC expanded its EAS requirements to include participation by digital television (DTV) broadcasters, digital cable television providers, digital broadcast radio, digital audio radio service (DARS) and direct broadcast satellite (DBS) systems. All requirements except the DBS requirement were to be implemented by Dec. 31, 2006. The DBS requirement is to be implemented by May 31, 2007. There have been indications that other target devices such as cell phone, PDA's and the Internet must be supported by the EAS. However, currently there are no requirements for EAS to support end user devices which are connected to the Internet via a digital subscriber line (DSL) modem.
There are other alert systems that broadcast notifications of various events to end user devices connected to the Internet; “Yahoo Alerts” is an example of such a notification system. However, these web alert systems are not reliable because they are not controlled by a centralized organization with first hand information about the respective event (are not part of the EAS). In addition, the existing systems likely have no influence on the telecommunications network that would carry the alert message to the end user; congestion in the Internet can prevent notifications from being delivered to an end user in a timely fashion. It is very unlikely that a web server owner could buy a service level agreement from a service provider, or carrier that would guarantee transport to all possible end DSL subscribers.
Due to the high number of DSL subscribers and the amount of time users spend using Internet services, it is possible that during a national, state, or local emergency, these users may not be notified of critical information. There is a need to specifically address the lack of EAS support for Internet end user devices, such as PCs.
To provide a reliable web alert system, the owner of the network must configure the network to give a guaranteed quality of service (QoS) such that alert messages are guaranteed to get to the end user device. There is a need to provide a reliable web alert system that uses an alert server strategically placed in a selected location in the network, such that the network can realistically be engineered to provide needed QoS for the alert messages.